How to drive 1KhzTone into Telephone circuit

Thread Starter

prevravanth

Joined Dec 29, 2006
8
Hi,

I am Generating 1 KHz tone in 80C51 using timer0.

I want this 1khz tone to be fed into Telephone.

this tone should be heared in Earpiece of telephone.

How to drive 1 Khz requency Tone into Telephone circuit...?

Please Help me.

Thanks
Prev Ravanth
 

thingmaker3

Joined May 16, 2005
5,084
You'll need an impedence matching circuit. The phone line is spec'd at 600 Ohms. If you measure actual phone line impedence and match to that instead, you gan get 3 or 4 dB improvement over a 600 Ohm match.
 
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